Carbon filled wrapper for smoking article

ABSTRACT

A carbon filled wrapper for smoking articles such as cigarettes, cigars and the like which significantly reduces the total particulate matter yield and organic vapor phase constituents in the mainstream smoke therefrom while simultaneously reducing the visible sidestream smoke. The carbon filled wrapper is preferably used as an inner wrapper for the tobacco column in combination with an outer wrapping of conventional cigarette paper or cigar wrap. The carbon content of the wrapper may vary over a wide range depending upon the effect desired. Various types of carbon, either activated or unactivated, may be used. Increased effects may be obtained if calcium carbonate is incorporated in the carbon filled sheet and the effects are further enhanced if the paper is treated with an oxidation catalyst such as the alkali metal hydroxides, bicarbonates and carbonates. The paper is also particularly suited as a means for introducing various flavorants to the cigarette since the carbon holds the flavor until released by the heat of the burning zone.

1111 3,744,496 14 1 July'l0, 1973 1 CARBON FILLED WRAPPER FOR SMOKINGARTICLE [75] Inventors: Stuart W. McCarty, Brevard; Donald T. Owen,Hendersonville; William F. Owens, Jr., Pisgah Forest, all of NC.

[73] Assignee: Olin Corporation, Pisgah Forest,

[22] Filed: Nov. 24, 1971 [21] Appl. No.: 201,837

52 Us. 01. 131/8, 131/15 R i Carpenter 131/15 R X OTHER PUBLlCATlONSDavis Manufacture of Paper(text) page 581 cited entitled ImprovedCigarette Paper pub by Henry Carey Baird and Co. 1886 PrimaryExaminer-Melvin D. Rein Att0rneyR0bert Habel [5 7] a ABSTRACT A carbonfilled wrapper for smoking articles such as cigarettes, cigars and thelike which significantly reducesthe total particulate matter yield andorganic vapor phase constituents in the mainstream smoke therefrom whilesimultaneously reducing the visible sidestream smoke. The carbon filledwrapper is preferably used as an inner wrapper for the tobacco column incombination with an outer wrapping of conventional cigarette paper orcigar wrap. The carbon content of the wrapper may vary over a wide rangedepending upon the effect desired. Various types of carbon, eitheractivated or unactivated, may be used. Increased effects may be obtainedif calcium carbonate is incorporated in the carbon filled sheet and theeffects are further enhanced if the paper is treated with an oxidationcatalyst such as the alkali metal hydroxides, bicarbonates andcarbonates. The paper is also particularly suited as a means forintroducing various flavorants to the cigarette since the carbon holdsthe flavor until released by the heat of the burning zone.

10 Claims, No Drawings CARBON FILLED WRAPPER FOR SMOKING ARTICLEBACKGROUND OF THE INVENTION This invention relates generally to smokingarticles such as cigarettes, cigars and the like, and the wrapper forthe tobacco column thereof, and more particularly to an improved wrapperfor such smoking articles which when used either by itself or as aninner liner in combination with conventional. wrappers significantlyreduces particulate and vapor phase constituents in the smoke drawnthrough the smoking article as well as reducing the amount of visiblesidestream smoke that normally emanates therefrom.

It has been the practice for a number of years to use various smokefiltering devices in cigarettes and other smoking articles to reduce theamount of certain constituents in the smoke. While some of these deviceshave been relatively successful, they still leave much to be desired inthe way of reducing many of the materials found in cigarette smoke.Cigarette papers are conventionally modified by the addition of variousburning chemicals to improve the burning rate and ash characteristics ofcigarettes as disclosed in U.S. Pat. Nos. 2,580,611, 2,652,834, and2,733,720, but such papers have little, if any, effect upon the contentof the cigarette smoke. Also, it is well known to use a calciumcarbonate filter in the production of cigarette paper to improve theappearance and properties of the paper as the above patents disclose.However, such conventional cigarette papers do not have a significanteffect upon the reduction of undesirable constituents in the cigarettesmoke.

A composite wrapper for cigarettes is disclosed in U. S. Pat. No.3,395,714 in which the outer wrapper is conventional cigarette paper andthe inner wrapper next to the tobacco column is a low-temperaturemelting point, heat-insulating plastic sheet material. Such acombination is stated to decreasethe burning zone temperature of thecigarette resulting in a lengthening of the cigaretteslow temperaturedistillation 'zone and an increase in the nicotine and flavor content ofthe smoke.

Various metal coated cigarette papers have also been suggested in theprior art. For example, U.S. Pat. No. 3,586,005 proposes a cigarettepaper wrapper in which the paper is coated on either or both surfaceswith a thin layer of a metal such as aluminum or aluminumbase alloys.The patentee asserts that cigarettes made with such wrappers have ahigher peak burning temperature and form a relatively continuous andunbroken sheath or tube around the burned and burning tobacco. This tubeis stated to oppose air entering the burning zone radially and acts as alengthwise conduit for the air so that more air passes through theburning zone over its entire cross section making more oxygen availablefor'more complete combustion and higher burning temperatures. However,the-use of such metal coated paper as a wrapper for cigarettes isimpractical since the long ash produced tends to pull the burning coneout of the cigarette when the ash is knocked off during smoking.

SUMMARY OF THE INVENTION It is an object of this invention to provide ameans for reducing the particulate and gaseous ingredients in the smokeof cigarettes, cigars and the like. A specific object is to provide ameans for reducing the quantity of gaseous components in cigarette andcigar smoke as well as reducing the particulate constituents thereof asthe smoking article is consumed without impairing the smokingcharacteristics thereof. A more specific object is to provide a wrapperfor the tobacco column of ciga rettes, cigars and the like whichaccomplishes the foregoing objects.

In accordance with this invention we have found that by using a carbonfilled wrapper for the tobacco column of a cigarette, cigar or similarsmoking article that the-mainstream smoke therefrom contains a reducedquantity of organic vapor phase components, and total particulate matternormally found in the smoke of such smoking articles made withconventional wrappers. In addition, the visible sidestream smoke fromthe cigarette or cigar is substantially reduced giving the appearance ofa smokeless cigarette or cigar during static burning.

The carbon filled wrappers of this invention may be made using anordinary paper furnish such as pulped wood or flax fibers to which isadded a sufficient quantity of pulverized carbon filler. The furnish offiber pulp and carbon filler is then used to make a paper sheet onconventional paper-making machines. The. particular fiber furnish fromwhich the carbon filled wrapper is made is not critical and any of thecellulosic fiber pulps used in paper making can be employed. The fiberpulps customarily used to make paper wrappers for cigarettes or thetobacco materials used to make cigar wrap are preferred. Thus, inadditionto wood and flax fibers, the furnish may be pulped tobaccostalks or stems to which is added the carbon filler or the carbon may beadded to the furnish used in making reconstituted tobacco sheets forcigar wrap.

Ideally, the carbon filled paper is used as an inner wrap under a normalouter wrap for the tobacco column of the cigarette or cigar.Conventional cigarette paper or cigar wrap is used as the outer wrappingfor the smoking article. Such a combination reduces the tobacco weightnecessary to make a satisfactory product, increases the tobacco rodfirmness and does not alter the appearance of the cigarette or cigarsince the outer wrap of conventional cigarette paper or cigar wrap hidesthe grey carbon filled inner liner.

In the case of cigarettes the construction is such that the carbonfilled paper inner wrap can be sealed or unsealed. If left unsealed, thesealed outer wrap holds the inner wrap around the circumference of thecigarette.

The carbon content of the wrapper may vary over a wide range dependingupon the reduction of vapor phase and particulate matter desired. Carbonamounts of at least 5 percent by weight based upon the weight of thepaper will give satisfactory results and amounts as high as percent canbe used successfully. Higher amounts of carbon filler tend to producegreater reductions in particulate and vapor phase constituents. Eitheractivated or unactivated carbon can be used in the carbon filledwrapper, although activated carbons are preferred. Carbons ranging frompulverized coal to very high activity coconut shell charcoal have beenused successfully. Other typical examples are activated wood carbons,activated mill waste carbons, activated coal and petroleum base carbons,unactivated bituminous coal, and pulverized charcoal briquettes.

From an appearance standpoint, the particle size of the carbon should besmall enough so that visible lumps do not show in the paper. This isgenerally more important when the filled sheet is used as an inner wrapin cigarettes since larger carbon particles produce visible lumps underthe cigarette paper outer wrap. Withcigars such lumps would be lessnoticeable and therefore not objectionable. Preferably, the carbon isfinely pulverized and we have found that particulate carbon that willpass through an 80 mesh screen or smaller is a desirable size range.

The carbon filled wrapper produces the desired effect without theaddition of any of the commonly used cigarette paper or cigar wrapburning chemicals. However, the use of burning chemicals appears to actsynergistically with the carbon to provide enhanced results in reductionof vapor phase components and total particulate matter in the smoke inaddition to providing better burning rate control. The most efficientburning chemicals that we have found are the alkali metal hydroxides,bicarbonates and carbonates, although there are many other commonlyknown burning chemicals that can be used such as citrate, phosphate andnitrate salts. It is also possible to use burning retardants incombination with the carbon filler to modify the combustion propertiesof the wrapper.

As discussed above, carbon in the wrapper alone provides most of thebeneficial effects in smoking articles. However, the use of an alkalineearth metal carbonate such as calcium or magnesium carbonate as anadditional filler material in thewrapper stock further enhances theeffects obtained over the use of carbon as the'sole filler material.Total particulate matter yield and the major organic vapor phase yieldare significantly reduced by the addition of calcium carbonate to thecarbon filled paper even when as little as 5 percent calcium carbonateby weight of the paper is added. Maximum reductions appear to beobtained with a total filler level of approximately 50 percent to 80percent by weight in the wrapper using carbon as the sole filler or acarbon/calcium carbonate filler mixture containing at least 5 percentcalcium carbonate by weight of the finished paper. Carbon/calciumcarbonate ratios may be varied as desired to produce different yields oftotal particulate matter, major organic vapor phase components in themainstream smoke, or the degree of visibility of the sidestream smoke.

The porosity of the carbon filled paper can be tailored to fit therequirements of the finished cigarette or cigar such as the air dilutionof the smoke desired. When the carbon filled paper is used as an innerwrap,

the porosity can vary over a wide range since porosity r of the totalwrapper in the finished cigarette or cigar can be controlled with theregular outer wrap.

This invention also provides an excellent method for the addition offlavorants to a cigarette or cigar since they are easily added to thecarbon filled paper. The carbon holds the flavorant until it is releasedby the heat of the burning zone to go into the sidestream or mainstreamsmoke. Menthol, vanillin, and glycyrrhiza are examples of commonflavorings for cigarettes and cigars that have been added to the carbonfilled paper and used with very satisfactory results.

Greater than 50 percent reductions in the total particulate matter yieldand major organic vapor phase yield in cigarette smoke have beenachieved in cigarettes made with carbon filled paper wrappers inaccordance with this invention. Similar dramatic effects are obtained inreducing the visible sidestream smoke.

, While we do not know with certainty why such reductions occur, it hasbeen determined that the carbon filled wrapper normally increases theburning temperature of the smoking article. It is believed that thisincrease in burning temperature, particularly at the skin of thecigarette or cigar, is important in reducing yields in the smoke fromcigarettes or cigars employing carbon filled paper wrappers, also thecarbon in the wrapper downstream from the burning zone may tend toadsorb certain constituents in the smoke.

PREFERRED EMBODIMENTS Typical results demonstrating the effects obtainedin accordance with this invention are described in the followingexamples which are illustrative of the invention only and are not inlimitation thereof.

EXAMPLE 1 Sample cigarettes were prepared using a carbon filled paperinner wrap for the tobacco column and a regular cigarette paper outerwrap. All samples were mm in length and approximately 8mm in diameter.The carbon filled paper inner wrap was made conventionally fromfiaxfiberpulp using an activated wood pulp carbon filler. The particlesize of the carbon was such that it would all pass through an meshscreen and approximately 25 to 50 percent would pass through a 325 meshscreen. Thefinal carbon filled sheethad a basis weight of 60 g/M and.contained about 70 percent by weight carbon. in half the samplesprepared, the carbon filled paper for the inner wrap was further treatedwith an oxidation catalyst consisting of 5 percent solution of sodiumcarbonate. For control purposes, identical cigarette samples wereprepared without a carbon filled paper inner wrap using the same tobaccoand cigarette paper. The following table sets forththe'results obtainedgiven as a per cent of the property measured as compared with thecontrol cigarette having no carbon filled paper inner wrap, measuringthe smoke obtained from burning 60mm of the tobacco column of eachcigarette.

TABLE I Cigarette with 5% Cigarette Na CO with plain treated carbon 1carbon Control filled paper filled paper cigarette inner wrap inner wrapProperty measured (percent) (percent) (percent) Mainstream totalparticulate matter yield 100 77 48 Mainstream major organic vapor phaseyield 100 70 4t) Visible sidestream smoke I00 53 Burning rate I01) 150Burningzone temperature 1 l5 I20 As the results in the above tableclearly show, the total particulate matter yield and major organic vaporphase yield in the mainstream smoke from cigarettes with the carbonfilled inner wrap are substantially reduced when compared with thecontrol cigarettes having a conventional cigarette paper wrapper. Verysubstantial reductions were also obtained in the visible sidestreamsmoke.

EXAMPLE II A number of carbon filled papers were prepared with differentactivities, types and amounts of carbon filler,

carbons tested was such that they would pass through an 80 mesh screenor smaller. The carbon filled papers were made by conventionalpapermaking techniques using flax pulp as the basic fiber and the weightof each of the finished sheets was approximately 60 g/M. Each of thecarbon filled sheets was then used in making a cigarette 70mm long andapproximately 8mm in diameter with the carbon filled sheet 'as the innerwrap for the tobacco column under a conventional cigarette paper outerwrap. Identical control cigarettes were prepared from the same tobaccoand using the same cigarette paper wrapping but without any carbonfilled paper inner wrap. In the following table the results are given asa per cent of the property measured compared with the control cigaretteshaving no carbon filled paper inner wrap. All results are based on thesmoke obtained from burning 60mm of each cigarette with approximately 10standard 35cc puffs per cigarette.

TABLE 2 Comparison of Activated and Unactivated Carbons TABLE 3 Effectwith Addition of Calcium Carbonate Filler V r P li e Side- T.P.M.Acrolein stream Description Yield Yield T.P.M. Carbon filled paper innerwrap Main- Main- Yield stream stream Medium Activity Mill Waste Carbon;

Paper contained 70% Carbon by weight; 72 mg Carbon per cigarette, No.CaCO;t 77% 54% 54% Medium Activity Mill Waste Carbon; Paper Contained50% Carbon by weight; 52 mg Carbon per Cigarette, mg CaCO, 74% 6I% 67%Medium Activity Mill Waste Carbon; Paper Contained 30% Carbon by weight;31 mg Carbon per Cigarette, 4| mg CaCO, 74% 59% 72% Medium Activit MillWaste Carbon; Paper Container l0 Carbon by weight; l0 mg Carbon perCigarette, 62 mg CaCO, u 74% 60% 78% TABLE 4 Effects with CalciumCarbonate and Burning Chemical Vapor Phase Side T.P.M. Acrolein streamDescription Yield Yield T.P.M. Carbon Filled Paper Inner Wrap' Main-Main- Yield stream stream High Activity Wood carbon; Paper Container 70%Carbon by weight; Paper Treated with 2.0% Solution of Na,CO 72 mg Carbonper Cigarette, No CaCO, 66% 44% 32% High Activity Wood Carbon; PaperContained 50% Carbon by weight; Paper Treated with 1.5% Solution ofNa,CO,; 52 mg Carbon per Cigarette, 20 mg CaCO, 73%

High Activity Wood Carbon; Paper Contained 30% Carbon by weight; PaperTreated with 1.0% Solution of Na CO 31 mg Carbon per Cigarette, 4] mgCaCO, 81%

High Activity Wood Carbon; Paper Contained l0% Carbon by weight; PaperTreated with 0.5% Solution of Na,CO;; 10 mg Carbon per Cigarette, 62 mgCaCO,

Similar beneficial results are obtained using carbon filled wrappersmade from wood pulp both with and without the additon of calciumcarbonate as the tiller. Also, while all of the above cigarettes testedemployed the carbon filled paper as an inner wrap under the conventionalcigarette paper outer wrap for the tobacco column, other samples testedusing the carbon filled paper as the sole wrapper produced similarreductions in the particulate and vapor phase yields of the cigarettes.Likewise, comparable results are obtained with carbon filled wrappersused as cigar wrap.

The effectiveness of the carbon filled wrapper of this invention forcigarettes and cigars is quite apparent from the foregoing illustrativeexamples. Many variations will become apparent to those skilled in theart, and the invention is not limited to the preferred embodimentsshown. Various modifications and changes may be made without departingfrom the spirit and scope of the invention as defined in the followingclaims.

What we claim is:

1. A smoking article of generally cylindrical form comprising a tobaccocharge, an intermediate wrapper for said tobacco charge, saidintermediate wrapper comprising a combustible porous paper sheet ofcellulosic fibers and finely pulverized carbon particles, said carbonparticles constituting at least 5 percent by weight of said sheet, andan outer wrapper for said tobacco charge selected from the groupconsisting of conventional cigarette paper and cigar wrap having goodcombustibility, said outer wrapper encircling and in contact with saidintermediate wrapper, whereby upon burning of the smoking article asubstantial decrease in the visible sidestream smoke emanating therefromis manifested while also reducing the constituents in the mainstreamsmoke as compared to a smoking article of the same composition withoutsaid intermediate wrapper. i

2. The smoking article of claim 1 in which said intermediate wrappercontains an alkaline earth metal carbonate, said carbonate constitutingat least 5 percent by weight of the intermediate wrapper.

3. The smoking article of claim 2 in which the alkaline earth metalcarbonate is calcium carbonate.

4. The smoking article of claim 1 in which the finely pulverized carbonused in said intermediate wrapper is medium to highly activated.

5. The smoking article of claim 1 in which the intermediate wrappercontains a flavorant absorbed by the carbon.

6. A composite wrapper adapted to encircle a to bacco charge in asmoking article, said wrapper constituting two superposed sheets, thefirst of said sheets comprising a porous paper sheet of combustiblecellulosic fibers and finely pulverized carbon particles, said carbonparticles constituting at least 5 percent by 7. The composite wrapper ofclaim 6 in which the first said sheet contains an alkaline earth metalcarbonate, said carbonate constituting at least 5 percent by weight ofthe first said sheet.

8. The composite wrapper of claim 7 in which the alkaline earth metalcarbonate is calcium carbonate.

9. The composite wrapper of claim 6'in which the finely pulverizedcarbon used in the first said sheet is medium to highly activated.

10. The smoking article of claim 6 in which the first said sheetcontains a flavorant absorbed by the carbon.

# i i l,

2. The smoking article of claim 1 in which said intermediate wrappercontains an alkaline earth metal carbonate, said carbonate constitutingat least 5 percent by weight of the intermediate wrapper.
 3. The smokingarticle of claim 2 in which the alkaline earth metal carbonate iscalcium carbonate.
 4. The smoking article of claim 1 in which the finelypulverized carbon used in said intermediate wrapper is medium to highlyactivated.
 5. The smoking article of claim 1 in which the intermediatewrapper contains a flavorant absorbed by the carbon.
 6. A compositewrapper adapted to encircle a tobacco charge in a smoking article, saidwrapper constituting two superposed sheets, the first of said sheetscomprising a porous paper sheet of combustible cellulosic fibers andfinely pulverized carbon particles, said carbon particles constitutingat least 5 percent by weight of the paper sheet, and the second of saidsheets selected from group consisting of conventional cigarette paperand cigar wrap having good combustibility, whereby when the compositewrapper is employed as the wrapper for a tobacco charge, with the firstsaid sheet positioned intermediate the tobacco charge and the secondsaid sheet, a substantial decrease in the visible sidestream smokeemanating from the smoking article is manifested during burning whilealso reducing the constituents in the mainstream smoke as compared to asmoking article of the same composition without said intermediatewrapper.
 7. The composite wrapper of claim 6 in which the first saidsheet contains an alkaline earth metal carbonate, said carbonateconstituting at least 5 percent by weight of the first said sheet. 8.The composite wrapper of claim 7 in which the alkaline earth metalcarbonate is calcium carbonate.
 9. The composite wrapper of claim 6 inwhich the finely pulverized carbon used in the first said sheet ismedium to highly activated.
 10. The smoking article of claim 6 in whichthe first said sheet contains a flavorant absorbed by the carbon.